The philosophers Aristotle, Kant, and Mill all proposed concepts of morality and virtue that, approached individually, appear reasonable to some degree. However, there is a major difference between Kant’s categorical imperative and the other two philosophies (Mill’s utilitarianism view and Aristotle’ doctrine of mean) in that unlike the other two, Kant’s categorical imperative is focused on and only deals directly with absolutes. It is for this reason that Kant’s point of view stands out when compared to the notable philosophies of Aristotle and Mill.

Aristotle’s doctrine of mean defines virtue or “arête” as a point of happiness achieved when one successfully holds to middle ground and avoids excesses. Aristotle is also similar to Mill because he argues that true happiness is the measurement of virtue and that excesses in any area cause unhappiness and degradation of virtue. A primary issue in this philosophy is that middle ground (or mediocrity as some may call it), is defined by Aristotle as “excellence.” Aristotle’s philosophy of virtue has other issues such as that it is relative and so what makes one person happy is virtuous (moral) to them only, and not universally moral or virtuous. This second point is a very serious issue because, as far as government is concerned, because it proceeds down a path that leads only to anarchy.

John Mill, similar to Aristotle, believed that every person is ultimately in pursuit of happiness, so happiness is an essential element in virtue. Where John Mill differs, is that utilitarianism philosophy extends beyond the single individual to encompass the greater good or happiness of the larger proportion of a community or population. Utilitarianism then, unlike the doctrine of mean, takes into consideration the consequences for actions, so that the actions that impact the greater number of people in a way that is good (producing happiness) is the right, virtuous and moral choice. However, utilitarianism still falls short because, just like the doctrine of mean, it is relative and is not absolute. Utilitarianism favors a “majority rules” concept in deciding what is virtuous. 

So both Aristotle and John Mill view the concept of morality as relative based upon either the individual or the greater community. Kant’s categorical imperative however, is quite different. Kant prescribes four tests that determine morality and virtue. Kant believes that morality must be based upon maxims that are universal and absolute.  The entire philosophy is based upon a primary maxim, which states ‘act only in accordance with that maxim through which you can at the same time will that it become a universal law’. And so, in order to test whether or not a choice is morally permissible, first create a maxim that includes the true reason for acting, and then apply that law universally, and then analyze whether or not it is conceivable that the world be ruled by this maxim. Finally, if a person could will to act on such a maxim in a world that is governed by the maxim, then the maxim is moral and virtuous.

Kant’s formula for determining and defining morality and virtue is definitely not without flaws. However, what is significant is that Kant attempts to define and absolute, rather than a relative morality in human terms. So Kant, rather than using individual or collective group happiness (such as is the case with Aristotle and Mill who both define philosophies which are relative and centered internally rather than universally) provides a solid definition that is not dependent upon outside circumstances or factors. For this reason it seems, Kant’s philosophy is the only one of the three that begins to truly define morality and virtue.